DESIGN FMEA TRAINING FOR LITENS AUTOMOTIVE

I S O / T S 1 6 9 4 9 R E G I S T E R E D • I S O 1 4 0 0 1 R E G I S T E R E D • w w w . l i t e n s . c o m

DESIGN FMEA Training developed for Litens Automotive

developed by Julian Kalac, P.Eng

Educational training for Litens Automotive

AGENDA TRAINING

Recap on DFMEA BASICS , FAILURE VS CAUSE,

DFMEA consequences of not doing it properly

PREVENTION CONTROLS

CRITICAL DIMENSIONS/TOLERANCES

Good vs Bad DFMEA Litens Examples

Design of Experiment –2𝑛 Factorial design

REVIEW / DEVELOPMENT OF YOUR DFMEA

CRITICAL DIMENSIONS AND TOLERANCES

September 15, 2016

Page 2

WORKING DFMEA 1-2HRS

TRAINING 2-3HRS

OBJECTIVE

Review the basics of Design FMEA

Consequences of poorly done DFMEA (GM Ignition Switch)

Learn to identify Single Point Of Failures SPOF, and ho to prevent them

Learn to use DOE to analyze surrogate data to optimize new designs

Learn basics about Design for Six Sigma (DFSS), process capability and design for loss of function

Review your Designs and DFMEA

September 15, 2016

Page 3

CANADIAN LAW

• Under Canadian law, manufacturers have a duty

1. DUTY TO WARN consumers of the dangers inherent in the use of their products of which the manufacturer has, or ought to have, knowledge.

2. NEGLIGENT DESIGN –manufacturer will be held liable under Canadian Law for foreseeable injury or damage caused by products that were negligently designed.

3. DEFECTIVE PRODUCT - manufacturer will also be held liable for any manufacturing defects

FMEA are specifically developed for that purpose.

September 15, 2016 Page 4

WHAT IS DFMEA ?

• Failure Mode and Effects Analysis (FMEA) is an engineering analysis tool used to identify and prevent failures before they actually happen

• DFMEA are used early in the development phase while the design can be changed as a Design Verification method

• The most efficient way to do a DFMEA is during the design review when, the entire design is being reviewed and the FMEA form can be used as a guide

• DFMEA IS NOT A FORM TO FILL OUT FOR COMPLIANCE REASONS

September 15, 2016

Page 5

September 15, 2016

WHAT IS DFMEA ? Page 6

Why is FMEA important?

1. Due Diligence – Product Safety Risks, Design Reliability, Regulations AIAG, CSA, OHSA, TS-16949 Design Verification,

2. Required for all new designs Proactively Identify and Prevent Design Failures (safety and performance) before the design is released into production

3. Reduces warranty costs - far less expensive to prevent problems early in product development than fix problems after launch.

4. Litens VP Engineering –Critical Dimensions MUST be DERIVED FROM DFMEA and tolerances justified –WHY IS THAT IMPORTANT?

WHAT ARE OUTPUTS OF A DFMEA

1. list of Critical Component Dimensions , their specifications (dim/tolerance) and evidence SHOWING how the Critical Tolerance relates to the Cause of Failure

2. A list of potential Failure Modes and Causes, prioritized by RPN

3. A list of action items that have been taken or will be taken to PREVENT the Failures Modes/Causes before PPAP

4. DVP Verification Plan (Conditions, Acceptance Criteria)

5. Lessons learned

FMEAs are legal documents

It is important for the FMEA team to

understand that FMEAs are legal

documents that support the

demonstration of due care in product

development. As legal documents, they

are subject to subpoena for legal

proceedings.

FMEAs, published by John Wiley & Sons. [1]

September 15, 2016 Page 9

FMEA SYSTEM BREAKDOWN

Is Sub-system = Sub-Assy ??

Types of FMEA

SYSTEM FMEA/CONCEPT FMEA

• Analysis is at highest-level of an entire system, (Vehicle) made up of various subsystems (electrical, front suspension,

• The focus is on top level interfaces/interactions between different subsystems and surrounding environment

• Looks at Single-point failures (where a single component failure can result in complete failure of the entire system)

• Example of System FMEA is an Application FMEA, focused on Application of an existing design

DESIGN FMEA

• Design FMEA evaluates the entire Product Design all levels contained within the boundaries of the product , (Final Assy, components, sub-assy)

• The scope of the Design FMEA includes the subsystem or component itself, as well as the interfaces between adjacent components.

• Critical dimensions are developed from critical failure modes within the DFMEA

• DVP&R Tests criteria are developed and confirmed

Process FMEA

• Process FMEA focuses on the design of the assembly process, development of process specifications in order to meet the critical dimensions specified in the DFMEA

• The scope of a Process FMEA can include manufacturing and assembly operations, shipping, incoming parts, transporting of materials, storage, conveyors, tool maintenance, and labeling.

WHEN TO DO A DFMEA?

Case 1: NEW DESIGNS, new technology, or new process. The scope of the FMEA is the complete design, technology or process.

Case 2: MODIFICATIONS TO EXISTING DESIGN or process (assumes there is a FMEA for the existing design or process). The scope of the FMEA should focus on the modification to design or process, possible interactions due to the modification, and field history.

Case 3: APPLICATION - Use of existing design in a new environment, or Application . The scope assumes there is an FMEA for the existing design or processes of the FMEA is the impact of the new APPLICATION or Environment on the existing design or process.

September 15, 2016

Page 17

September 15, 2016

Consequences of not doing a DFMEA Page 18

September 15, 2016

DO NOT WAIT FOR THIS TO HAPPEN PREVENTED

Page 19

September 15, 2016

BECAUSE THIS IS THE EFFECT

Page 20

September 15, 2016

GM IGNITION SWITCH FAILURE

Page 21

OVER 300 deaths 23 Mil cars recalled from 2004 2014

GOOD PRACTICES TO AVOID BAD EVIDENCE

FMEA • It has to be done correctly: • A well-done and properly completed FMEA can be a

strong ally in the defense for the manufacturer in product litigation.

• On the other hand, a poorly done and haphazard completion of an FMEA can be used to support the prosecution. September 15, 2016 Page 22

September 15, 2016

IDENTIFY POTENTIAL FAILURE MODES WITH IGNITION SWITCH

Page 24

September 15, 2016

GM IGNITION SWITCH FMEA Page 26

GM IGNITION SWITCH FMEAFAILURE MODE FAILIURE EFFECT S CAUSE OF FAILURE O

DESIGN

CONTROLS D RPN RECOMMENDED ACTION

STALLS VEHICLE ON

HIGHWAY---NOT

SAFETY CAN STEER

CAR OFF TO THE SIDE-

-DRIVER NUISANCE

10

IGNITION SWITCH

REQUIRES LOW TORQUE

TO TURN --KEY CHAIN

TOO HEAVY --

1

FOB

SPECIFICATI

ON FOR

WEIGHT

1 8

ISSUE TSB TO REMOVE ALL

KEYS FROM FOB -CLOSE

FMEA

DRIVER NUISANCE 8 IGNITION SWITCH LOW TORQUE 2VEHICLE

RESTART1 8 NONE CLOSE FMEA

Requirement not defined in units of measure (VALUES)

Lessons Learned from GM ignition Switch

The Federal Crown Prosecutor report suggest that the original GM ignition switch specification contained vague and ambiguous targets for the detent torque, which were never achieved, and provides no evidence that the specification or acceptance criteria were developed using failure modes effects analysis or similar techniques.

As a direct result GM engineers failed to understand the significance of the available evidence for over ten years - and they never asked "Is the specification is fit for the purpose?" - with serious consequences for the company and it's consumers.

September 15, 2016

Page 27

September 15, 2016

EXPLOSIVE PINTO FUEL TANK DESIGN

Page 28

DFMEA and PFMEA connection

Critical / special

characteristics

Brooks Approval:

Date Approved:

Effectivity Date:

Part Number: PCP Number Prepared by:

Part Number Revision: PCP Revision Checked by:

Part Name: PCP Rev Date: Approval:

Characteristic Description

Specification

&

Tolerance

Key

DimMeasurement Technique

Sample size&

FrequencyRecord

CoC Verification Every lot

Dimensions caliperAQL 1.0

Every lot

diameter Ø160±1 CMM

diameter Ø130±1 CMM

diameter Ø120 G6 Y CMM

diameter Ø65±.0.1 CMM

chamfer C2 CMM

dim 10 -0.1/0 HG

dim 5±0.2 HG

dim control 19 to19.2 Caliper

Roughness 63 √ C SRT/Comparator

3rd Process,

0.02 Y CMM

0.02B Y CMM

Ø0.02B Y CMM

4th process

Hole Ø5H8 PG

dim 26.5±0.03 Y CMM

Tap M6 Tap hole Thread Gauge

HoleØ4.5(all the hole

dimension)CMM

50 De-Burring De-burring tools work instruction #: xxxxBreak All Sharp

Edges and burrsvisual Inspection

AQL1.0

every lot

Record on QA Plan

XXXX

StopDe-

burringRework &

CAR

Tap M6 Tap hole Thread Gauge

Hole Ø5H8 PG

Roughness 63 √ C SRT/Comparator

Appearance to Spec XXXX Visual inspection

70Treatment/Finish

ingTreatment House

Specification #:xxxx

Treatment PCP #:xxxxx Electroless Nickel Plating [0.003-0.005mm]

X-Ray Visual

inspection

AQL0.65

Every lotCOC from Supplier Rework

Qualified Plater

(ABC Company)

diameter Ø120 G6 CMM

hole Ø5H8 PG

tap M6 Tap hole TG

roughness All surface Roughness SRT/Comparator

AppearanceNo stain, masking,

color to sampleVisual inspection

90 Packagingwork instruction xxx-

xxxxVisual

Each Lot

Received

STD packaging

method

Repack and

Validate

100Out Going

Inspection

work instruction xxx-

xxxx

Refer to out going inspection

sheert

CMM

Visual

AQL 1.0 Every

lot

Review of QA Plan

XXXXXRaise CAR/Rework

Supplier Name:

Process Control Plan

Supplier Number:

Workcell / Location

Pro

cess

Ste

p

Nu

mb

er

Process Name /

Operation

Description

Machine, Device, Jig,

Tools for

Manufacturing

Ref Doc. Number/

Specification No

Control Methods/Measurement

Reaction PlanRemarks

(Special Process)

10work instruction xxx-

xxxx

STEEL, CORROSION RESISTING, 304 OR 304L IQC inspection

sheet

Product / Process Characteristics

Receive Raw

Material

Incoming

Return to Supplier.

RMA process XXX

Notify production of new

delivery date.

40Manufacture work

instruction #: xxxx

Machining

Hole, Profile

cutting, Tap

holes

30Manufacture work

instruction #: xxxxBottom plane

CNC Milling#:xxx

Tool #:xxx

Fixture#:xxx

20

Drawing #:xxx

Manufacture work

instruction #: xxxx

80Post-treat Inspection

procedure xxxx

Pre-Treatment

Post-Treatment

Inspection

60Specification #:xxxx

Treatment PCP #:xxxxx

Machining

N/A

CNC Lathe#:xxx

CNC Program #:xxxx

Tool#:xxxx

Fixture#:xxxx

Grinding#:xxx

Tool #:xxx

Fixture#:xxx

2pcs Every

machine Set up

1pcs every two

hours

In-Process

In-Process Insp.

From CMM

2pcs Every

machine Set up

1pcs every hour

In-Process

In-Process Insp.

From CMM

2pcs Every

machine Set up

1pcs every two

hours

In-Process

In-Process Insp.

From CMM

AQL0.65

Every lot

Pre-treatment

inspection record

AQL0.65 for

critical

dimensions and

100% for Visual

inspection

COC from

supplier and Post

treatment

inspection record

Rework/CAR send

for rework

Raise CAR send for

rework

Stop machining/

Fine-tune the

Setting and re-

inspect

Notify Supervisor

Stop machining/

Fine-tune the

Setting

Qualified Operator

Stop machining/

Fine-tune the

Setting

Critical Dimensions & tolerances from DFMEA

DFMEA and DVP&R connection

Test description input

to the DVP&R.

Email: Email:

Phone: Phone:

Fax: Fax:

Sample

Size or

Truck #

Req. Start End Start End

1)

Material Compliance

DRD# 3.2.3.1.1

Rev #

Dated ##/##/##

Per CEMS D-28

Rev #

Dated ##/##/##

1a) No 6.3 Resin Requirements Table 2 1 day PVAll Must

PassD 1 Lot 2013-12-31 2013-12-31

84576 by

GED 1 2013-12-31 2013-12-31 1 Lot

1b) No6.3 Specific Gravity Table 4 Per ASTM

D792 1 day PV

All Must

Pass

Test

PlaquesD 1 Lot 2013-12-31 2013-12-31

84576 by

GED 2 2013-12-31 2013-12-31 1 Lot

1c) No

6.3 Tensile Strength - Ultimate

Table 4Per ASTM

D6381 day PV

All Must

Pass

Test

PlaquesD 1 Lot 2013-12-31 2013-12-31

84576 by

GED 3-4 2013-12-31 2013-12-31 1 Lot

1d ) No 6.3 Ultimate Elongation Table 4Per ASTM

D6381 day PV

All Must

Pass

Test

PlaquesD 1 Lot 2013-12-31 2013-12-31

84576 by

GED 5-6 2013-12-31 2013-12-31 1 Lot

1e) No 6.3 Flexural Modulus Table 4Per ASTM D

7901 day PV

All Must

Pass

Test

PlaquesD 1 Lot 2013-12-31 2013-12-31

84555 by

GED 5-6 2013-12-31 2013-12-31 1 Lot

1f) No6.3 Flexural Strength Table 4 Per ASTM D

7901 day PV

All Must

Pass

Test

PlaquesD 1 Lot 2013-12-31 2013-12-31

84576 by

GED 7-8 2013-12-31 2013-12-31 1 Lot

1g) No

6.3 Impact Resistance Table 4

Per CEMS-DT-4 /

Rev #

Dated ##/##/##

Per ASTM D

7901 day PV

All Must

Pass

Test

PlaquesD 1 Lot 2013-12-31 2013-12-31

84576 by

GED 9-10 2013-12-31 2013-12-31 1 Lot

1h) No

6.3 Deflection Temperature

Table 4Per ASTM D

7901 day PV

All Must

Pass

Test

PlaquesD 1 Lot 2013-12-31 2013-12-31

84576 by

GED 11-12 2013-12-31 2013-12-31 1 Lot

1i) No 6.3 Color Table 4 1 day PVAll Must

Pass

Molded Part

Detail D.01D 2 Parts 2013-12-31 2013-12-31 ASD256 D 13-14 2013-12-31 2013-12-31 2 Parts

1j) No6.3 Dimensional Stability Table

44 hours PV

All Must

PassMolded Part B 2 Parts 2013-12-31 2013-12-31

ETA Lab

Rpt 56843C 13-14 2013-12-31 2013-12-31 2 Parts

2) No 6.3 Table 4 Other Characteristics 1 day PVAll Must

PassPlated part C 1 Part 2013-12-31 2013-12-31

HB dated

8/21/06C 15-16 2013-12-31 2013-12-31 8 parts

3) No 6.3 Table 4 Other Characteristics 1000 Hours PVAll Must

PassPainted part C 1 Part 2013-12-31 2013-12-31

LCL

Reported

9/29/06

C 17-18 2013-12-31 2013-12-31 9 PartsZ2 = Finish Paint per TMS-9008 Color: Argent, NAV

8752Pass Accept

Testing completed by Supplier

see Paint TabGrille, Painted, Fixed

Testing to be

completed by Supplier

see Paint Tab

Z1 = Chrome Plate per MS-7071B_fk Pass Accept

Testing completed by FGH

Platers, Inc, See Chrome Plate

Tab

Salt Spray applied at 16,

32 56 Hours (Grille,

Chrome, Fixed )

Testing to be

completed by FGH

Platers, Inc, See

Chrome Plate Tab

AA88 = 4 hours at 88° C

Parts will conform to the dimensions and tolerances shown

on the engineering drawings after four hours exposure in

an oven at the temperature indicated by the numeral of the

suffix AA - symbol expressed in degrees Celsius.

Pass AcceptPart Testing Performed by ABC

on Molded Part

Molded part (No

Assembly)

Part Testing to be

performed by ABC

AC1 = Integrally colored Part Pass Accept Verified by ABC To be verified by ABC

S90 = 90° min. deflection temperature at 1820 Kpa98 C

AcceptMaterial Testing Performed by

GE on Test Plaques

Material to be tested

by GE

R235 = 36 in/lbs force at minus 30° F

Parts will show no evidence of cracking when impact

tested at point or points indicated on engineering drawing.299 in-lbs. - Material


GE on Test Plaques


by GE

N60 = 60 MPa min.72 MPa


GE on Test Plaques


by GE

M17 = 1700 MPa min.2060 MPa


GE on Test Plaques


by GE

L100 = 100% min. 150% AcceptMaterial Testing Performed by

GE on Test Plaques


by GE

K-40 = 40 MPa min. 50 MPa AcceptMaterial Testing Performed by

GE on Test Plaques


by GE

DF1140 = 1.140+/- 0.05 01-Jan-00 AcceptMaterial Testing Performed by

GE on Test Plaques


by GE

PC+ABS = Polycarbonate + Acrylonitrile / Butadiene /

Styrene

PC+ABS = Polycarbonate

+ Acrylonitrile / Butadiene /

Styrene


GE


by GE

Sample IDActual Timing Sample

Size Tested

PC + ABS DF1140 K40 L100 M17 N60 R235 S90 /

AC1 AA88 Z1 Z2

Test Location / Test

Verification Resp.

Rqmt

Source

Sample

Type

Scheduled TimingReport #

Sample

LevelActual Results

Test Results Status

Accept / RejectTests Completed by Notes / Remarks Test Stage

Target

RqmtsTe

st

Nu

mb

er

Compliance /

Regulatory /

S C/CC/KP C

Specification / Test Name

Test Method

or Test

Procedure

Duration of

TestAcceptance Criteria

630-123-4568 815-123-4568

Testing details and Results Planning information Actual Timing

[email protected] [email protected]

Test Stage ED = Engineering Devel't Test, DV = Design Verification, PV = Production Verification, CCT = Continued Compliance Testing

Target Requirements. State required probability or reliability and confidence of meeting criteria, e.g. R90, C90 or all must pass. Sample

Type / Level A = Prototype (Handmade), B = Prototype (Tooled), C = Production Tool (Not Process), D = Production Tool & Process

630-123-4567 815-123-4567

Title: Chief Engineer Title: Engineering MGR

Grille, Chrome, Fixed 123659749 C

State: MN Country:

Zip / Postal Code: 60586

X

Component (s):w/ Navistar Part

Number(s)Rev

USA

Grille, Chrome, FIxed 1315449691 D

Navistar Design Engineer Supplier Design Engineer (Key Contact)

Grille, Asm 23614649 AName: Steve Peterson Name: James Foley

Grille, Asm

Assembly Name:w/ Navistar Part

Number(s)Rev Supplier

Address: 12364 Jackson St.

23614649 B

City: Andrewsville

Date:

1236364 A 2012-02-13Subsystem: Grille Fixed Supplier Code: 12345 Affected Navistar Program(s): XVY 1235

DESIGN VERIFICATION PLAN AND REPORT ISQ-011-FO

Rev: A Date: 04/01/2013

System: Exterior Trim Supplier Name: One, Two, Three 123 Inc. Core Team:

(list names)

A. Hernandez, B. McGruff, S. Orlander, K.

Keller

DVP&R Number: Revision Level:

DVP&R example

Acceptance Test Criteria from DFMEA---example Min Torque= 70Nm

FAILURES, SYMPTOMS AND ROOT CAUSE ANALYSIS

Design FMEA 34

Failure Mode

ANTI-FUNCTION

(FAILURE MODE)

2016-09-15

FMEA Thought Process 35

9/28/2013

DFMEA --# 1 QUESTION: WHAT CAN GO WRONG?

36

1. Ask Leading question “what can go wrong inside the design that would prevent it from functioning?”

2. Once a Failure is identified then ask the question: If this failure occurred, then what could happen?

Failure Modes & Causes

Failure Modes: Identify the manner in which an item could potentially fail to meet it’s design intent. Example

BROKEN Spring, DEFORMED Housing, Seal Leak

Piston SEIZES , Valve Port BLOCKED, Oil Contaminated

CAUSE: is the component feature that created the failure condition

Broken Spring Cause: Yield strength of spring exceeded

September 15, 2016

Page 37

A single point of failure (SPOF) is an undesired component/part if it fails, will cause the entire system to fail,

SPOF can be an Assembly (master brake cylinder Assy) or a single component (air bag sensor)

It could be at the top level of the system (air bag sensor) or deep internal not visible to the user (master brake cylinder)

SPOF are identified in FMEA as Critical (Y C) or Special Characteristics (SC) and will relate directly to a severe failure mode (sev 8 or higher)

September 15, 2016

SINGLE POINT OF FAILURE (SPOF)

Page 38

39

Failure Mode = Flood With Water

Symptoms = Pipes Leaking

POSSIBLE ROOT CAUSE(S) = 1. Condensation from pipes due to

temperature change OR/AND

2. Faulty Gasket OR/AND ,

3. Corroded Pipe Fittings OR

4. Over-Pressurized Pipes OR

5. ………………

$ $ $

$ $ $ $

$ $

$ $

Root Causes vs. Symptoms of Failure Modes

DFMEA INPUTS/OUTPUTS

The following elements/tools may provide input to the DFMEA: • Requirements, (Customer, Product Specs, Regulatory, etc.)

• Historical performance-Warranty/Field Returns, failures, Recalls,

• Free Body Diagram

• P-Diagram

• FEA Analysis

• Boundary Diagram and Interface Matrix

• Functional Block Diagram

• WC -Tolerance Stack Up Analysis, RSS, % Contribution, Monte Carlo,

• Stack Up Analysis

• DESIGN of Experiment DOE

DFMEA INPUTS

DFMEA OUTPUTS (MANDATORY)

1. A list of Critical Component Characteristics and their specifications (dim/tolerance) (PFMEA & CONTROL PLAN)

2. A list of potential Failure Modes and Causes, prioritized by RPN

3. A list of Design action items to PREVENT the Failures/Causes

4. DVP Verification Plan (Conditions, Acceptance Criteria)

5. Lessons learned

BOUNDARY DIAGRAM—SYSTEM

Catalytic Converter Assy

September 15, 2016

INTERFACE MATRIX –FAILURE MODES

Page 44

P-DIAGRAM—CAUSES OF FAILURE

Catalytic Converter Assy

Y= f (x1, x2, x3,….)

Y=OUTPUT X=INPUT

Prepared By: Julian Kalac Date: 11-Jun-16

Stack Description: To determine the tolerance between the flange hard stop and sensor surface for the Cmount Cover.

Starting Point: Flange Hard Stop

Ending Point: Sensor Surface

From To

Upper

Tolerance

Lower

Tolerance

Upper

Limit

Lower

Limit

1 Flange Hard Stop Sensor Mount Front + 16.150 0.050 -0.050 16.200 16.100 16.200 16.100 0.100

2 Sensor Mount Front Sensor Mount Rear + 2.000 0.050 -0.050 2.050 1.950 2.050 1.950 0.100

3 Sensor Mount Rear Shim Rear + 0.127 0.000 0.000 0.127 0.127 0.127 0.127 0.000

4 Shim Rear Sensor Surface - 0.750 0.060 -0.060 0.810 0.690 -0.690 -0.810 0.120

A positive or negative Max or Min total indicates only the DIRECTION from the STARTING point to the END point of the stack. Totals: 17.687 17.367

0.093

Mean + Statistical Tolerance = 17.620

Mean - Statistical Tolerance = 17.434

Total Target Dimension= -17.527

Desired Distance for C-Mount Flange Focal Distance = 17.526 +/- .1


Stack Description: To Determine the required tolerance in the gap appearing on the outside of the housing between the Front Housing and Rear Housing

Starting Point: Exterior Gap Front

Ending Point: Exterior Gap Rear

From To

Upper

Tolerance

Lower

Tolerance

Upper

Limit

Lower

Limit

1 Exterior Gap Front Flange Hard Stop - 43.980 0.050 -0.050 44.030 43.930 -43.930 -44.030 0.100

2 Flange Hard Stop Sensor Mount Front + 28.700 0.050 -0.050 28.750 28.650 28.750 28.650 0.100

3 Sensor Mount Front Sensor Mount Rear + 2.000 0.050 -0.050 2.050 1.950 2.050 1.950 0.100

4 Sensor Mount Rear Housing Rear + 30.100 0.050 -0.050 30.150 30.050 30.150 30.050 0.100

5 Housing Rear Exterior Gap Rear - 16.500 0.050 -0.050 16.550 16.450 -16.450 -16.550 0.100

A positive or negative Max or Min total indicates only the DIRECTION from the STARTING point to the END point of the stack. Totals: 0.57 0.07

0.112


Mean - Statistical Tolerance = 0.208

Total Target Dimension= 0.224


Stack Description: To determine the varying distance between the rear of the coax board and interior wall of the rear housing

Starting Point: Flange Stop Surface

Ending Point: Housing Rear

From To

Upper

Tolerance

Lower

Tolerance

Upper

Limit

Lower

Limit

1 Sensor Board Rear Shims + 0.127 0.000 0.000 0.127 0.127 0.127 0.127 0.000

2 Shims Sensor Board Rear + 0.787 0.079 -0.079 0.866 0.709 0.866 0.709 0.157

3 Sensor Board Rear Stand Off + 4.500 0.087 -0.087 4.587 4.413 4.587 4.413 0.174

4 Stand Off FPGA Board + 1.575 0.158 -0.158 1.733 1.417 1.733 1.417 0.316

5 FPGA Board Stand Off + 4.500 0.087 -0.087 4.587 4.413 4.587 4.413 0.174

6 Stand Off MISC Board + 1.575 0.158 -0.158 1.733 1.417 1.733 1.417 0.316

7 MISC Board Stand Off + 4.500 0.087 -0.087 4.587 4.413 4.587 4.413 0.174

8 Stand Off Coax Board + 1.575 0.158 -0.158 1.733 1.417 1.733 1.417 0.316

9 Coax Board Interior Read Housing + 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

10 Interior Read Housing Housing Rear Rear + 7.200 0.050 -0.050 7.250 7.150 7.250 7.150 0.100

11 Housing Rear Rear Sensor Mount Rear - 30.250 0.050 -0.050 30.300 30.200 -30.200 -30.300 0.100

A positive or negative Max or Min total indicates only the DIRECTION from the STARTING point to the END point of the stack. Totals: -2.9971 -4.8245

0.330

Mean + Statistical Tolerance = -3.581

Mean - Statistical Tolerance = -4.241


**For component/dimensions in parrellel (standoff and connectors) the average standard deviation is used, [AveTolerance]=[Tolerance]/[sqrt(number of parrellel features)]


Stack Description: To determine the varying distance between the optical center of the housing and sensor

Starting Point: Optical Center

Ending Point: Sensor Center

From To

Upper

Tolerance

Lower

Tolerance

Upper

Limit

Lower

Limit

1 Optical Center on Housing Front 2 Alignment Holes Axes + 0.000 0.035 -0.035 0.035 -0.035 0.035 -0.035 0.070

2 2 Alignment Holes Axes Hole Side (1/2 Dia) + 0.000 0.005 -0.005 0.005 -0.005 0.005 -0.005 0.010

3 Hole Side (1/2 Dia) Dowel Axes + 0.000 0.001 -0.001 0.001 -0.001 0.001 -0.001 0.001

4 Dowel Axes Reference Planes on Sensor Mount + 0.000 0.050 -0.050 0.050 -0.050 0.050 -0.050 0.100

5 Reference Planes on Sensor Mount 3 PCB Screw Holes Axes + 0.000 0.029 -0.029 0.029 -0.029 0.029 -0.029 0.058

6 3 PCB Screw Holes Axes Sensor Placement on PCB + 0.000 0.025 -0.025 0.025 -0.025 0.025 -0.025 0.050

A positive or negative Max or Min total indicates only the DIRECTION from the STARTING point to the END point of the stack. Totals: 0.1444 -0.1444

0.123


Mean - Statistical Tolerance = -0.123


Statistical tolerance [sqrt(sum of sqrd tol)*3] =

STACK-UP SPREADSHEET

Description

Stack Direction +/-

Target

Dimension

Bi/Unilateral Dimension Limit Dimension+ Max

- Min

+ Min

- MaxTolerance


Bi/Unilateral DimensionDescriptionTarget

Dimension

Limit Dimension+ Max

- Min

+ Min

- MaxTolerance

Stack Direction +/-

Limit Dimension+ Max

- Min

+ Min

- MaxTolerance




Description

Stack Direction +/-

Target

Dimension

Bi/Unilateral Dimension Limit Dimension+ Max

- Min

+ Min

- MaxTolerance



Description

Stack Direction +/-

Target

Dimension

Bi/Unilateral Dimension

STACK UP ANALYSIS---DESIGN PREVENTION

September 15, 2016

FEA ---DESIGN PREVENTION

Page 47

WHAT ARE YOU PREVENTING ? 1. MAX LOAD FAILURE 2. FATIGUE FAILURE 3. SINGLE POINT FAILURE

Remaining Life Analysis ( RLA )

Durability Analysis

Failure Prediction Analysis

High Cycle Fatigue Calculations

Correlation to Real-world situations

Comparison of Alternate materials for extended life and warranty

Life extension analysis

September 15, 2016

Fatigue Analysis - DESIGN PREVENTION Page 48

Monte Carlo Analysis---DESIGN PREVENTION

PREVENTION CONTROLS

DETECTION CONTROLS

1. Design Specifications

2. Critical Characteristics

3. Test to Failure

4. Durability Testing

5. Design Validation Testing

6. End of Line Testing

METHODS FOR PREVENTION AND DETECTION

1. Stack up Analysis

2. DOE—Design of Experiment

3. FEA Analysis

4. Engineering Design Standards, ANSI, CSA, ASTM, NFPA, ISO

FMEA RPN

51

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

0

5

10

15

20

25

30

35

40

45

PRIORITIZING FAILURES 80/20 RULE

RPN CUMULATIVE PERCENT Expon. (RPN )

Top 2 failures= 80% TOTAL FAILURES

September 15, 2016

DO NOT WAIT FOR THIS TO HAPPEN PREVENTED

Page 52

NEXT LET’S REVIEW OF YOUR DESIGN FMEA

September 15, 2016

Page 53

THANK YOU